Duplex-cylinder pin-tumbler lock.



J. H. SHAW & F. I. KIMBALL.

DUPLEX CYLINDER PIN TUMBLBR LOGK.

APPLICATION FILED NOV. 24, 1911.

.v 1,01 3 Patented Feb. 27, 1912.

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COLUMBIA PLANOGRAPN IO-,WASHINCTON, D c.

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JOHN H. SHAW, OF NEW HAVEN, AND FRANK It. KIMBALL, OF WEST HAVEN, CON- NECTICUT, ASSIGNORS TO SARGENT & (30., OF NEW HAVEN, CONNECTICUT, A.

CORPORATION.

DUPLEX-CYLINDER. PIN-TUMBLER LOCK.

Specification of Letters Patent.

Patented Feb. 2'7, 1912.-

To all whom it may concern:

Be it known that we, JOHN H. SHAW and FRANK I. KIMBALL, citizens of the United States, residing, respectively, at New Haven and West Haven, in the county of New Haven and State of Connecticut, have invented a new and useful Improvement in Duplex-Cylinder Pin-Tumbler Locks; and we do hereby declare the following, when taken in connection with the accompanying drawings and the characters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent, in

Figure 1 a view in front elevation of an extensible pin-tumbler lock constructed in accordance with our invention. Fig. 2 a view thereof in side elevation showing its provision with the shortest of its interchangeable extensions. Fig. 3 a view of the lock in rear elevation. Fig. 4 a view of the lock in horizontal section on the line a-b of Fig. 8. Fig. 5 a view of the lock in vertical longitudinal section. Fig. 6 a view of the lock in rear elevation with the extension removed. Fig. 7 a detached View in inside elevation of the extension. Fig. 8 a detached View of the extension in horizontal section on the line c-cl of Fig. 7. Fig. 9 a detached view in perspective of the bit. Fig. 10 a corresponding view of the sliding coupler. Fig. 11 a corresponding view of the supplemental plug. Fig. 12 a detached view in elevation of the plug-retaining plate. Fig. 13 a detached view in vertical longitudinal section of the short extension. Fig. 14 a corresponding view of the intermediate extension. Fig. 15 a corresponding view of the long extension.

Heretofore one of the most serious objections to duplex cylinder pin-tumbler locks has been the difficulty of making the duplex cylinder harmonize with the standard bit. Prior inventors have proposed the enlargement of the entire lock-structure to get around this difficulty-only to encounter the greater difficulty of thus increasing the locks beyond the standard size and so handicapping their sale, since locks of this character are now well standardized.

With the end in View of producing duplex cylinder pin-tumbler locks of standard size and having standard bits, our invention consists in providing a sliding coupler between the plugs of such locks and their hits, whereby the eccentric throw of the outer plug is compensated for and equalized by the sliding coupler.

Our invention further consists in certain details of construction and combinations of parts as will be hereinafter described and pointed out in the claims.

In carrying out our invention as herein shown, we employ a sliding coupler or dog 2 adapted to slide transversely to the longitudinal axis of the lock in a slot 3 extending transversely across the projecting inner end of the key-plug 4 which is eccentrically mounted in an eccentric or outer plug 5 which in turn is mounted in the cylinder 6 which is of ordinary construction and of standard size. As shown the lock is provided with five three-part pin-tumblers 7 operated by spiral springs 8, these tumblers and springs being of ordinary construction and operation. The said sliding coupler 2 is formed upon its rear face with a centrally arranged transverse coupling-lug 9 adapted to enter a coupling-slot 10 extending transversely across the forward face of a supplemental plug 11 mounted in each of a series of interchangeable cylinder-extensions 12, 13 and 14, all corresponding to each other except in length, and in the length of their supplemental plugs 11 and designed to be interchangeably fastened to the inner end of the pin-tumbler lock cylinder 6 according as the door to which the lock is applied is thin, of medium thickness or thick. The said cylinder extensions 12, 13 and 14 are formed with circumferential threads 15 for the application of the pin-tumbler lock cylinders in the usual manner to the bolt-locks which are mortised into the doors.

It will be understood that the slidin coupler 2 is free to slide lengthwise in the slot 3 of the plug 4, and that its couplinglug 9 is free to slide lengthwise in the slots 10 of the supplemental plugs 11, whereby the sliding-coupler 2 accommodates itself to the changes in the centers of the two plugs 4 and 5 as they are rotated, due to the fact that the inner plug 4 is mounted to one side of the center of the outer plug 5. We may mention in this connection that in ordinary pin-tumbler cylinder locks, the key-plug corresponding to the plug 4 is located substantially one-sixteenth of an inch from the lower edge of the cylinder 6, whereas in duplex pin-tumbler cylinder locks the keyplug has to be raised about one-sixteenth of an inch from its original position in order to make room for the outer or eccentric plug.

The supplemental plugs 11 of the respective cylinder extensions 12, 13 and 14, are each provided at their rear ends with an oblong assembling-lug 16 entering a corre sponding assembling-slot 17 in a standard bit 18 secured to the supplemental plug 11 by two screws 19 which hold an annular retaining-shoulder 20 formed at the forward end of the plug in place in an annular recess 21 in the bottom of the counterbore 22 formed in the forward face of each of the cylinder extensions 12, 13 and 14, whereby each cylinder extension has its supplemental plug 11 and bit 18 permanently assembled with it but free to rotate within it as one piece. The counterbore 22 formed in the inner face of each of the cylinder-extensions 12, 13 and 14 adapts the same to fit over the projecting inner end of the outer or eccentric plug 5.

For the purpose of holding the two plugs 2 and 5 against endwise displacement with respect to each other and with respect to the cylinder 6, we employ a plug-retaining plate 23 fastened by screws 24 to the rear end of the outer plug 5 in position to have its edge bear upon the rear end of the cylinder 6. A portion of the inner edge of the said plate 23 enters a peripheral groove 25 formed in the rear end of the said plug 5, which is thus held against endwise displacement with respect to the said cylinder, while an'extension 26 of the plate 23 enters a peripheral groove 27 in the rear end of the key-plug 4 and holds the same against endwise displacement with respect to the plug 6, but both plugs are left free to rotate in either direct-ion independently of each other. We do not, however, claim a plug-retaining plate such as 23 constructed and arranged to perform the two fold office of holding the key-plug 4 and the outer plug 5 of a duplex cylinder lock, against endwise displacement with respect to each other and to the cylinder 6, the said plug-retaining plate when so used, forming the subject matter of another application.

It will be seen from the foregoing, that by means of our improved sliding coupler, a bit of standard size may be used in conjunction with a duplex pin-tumbler cylinder of standard size, since the coupler being free to slide both with respect to the supplemental key-plug 2 and to the outer or eccentric plug 5 always equalizes the difference at any given time in the separation or non-alinement of their longitudinal centers. Our invention therefore enables duplex pin-tumbler cylinder locks to be standardized with other locks of the same character. However, a coupler may be used to connect the inner end of a key-plug with a supplemental plug permanently mounted in a cylinder-extension, irrespective of whether the lock is duplex in its character or not.

l/Ve claim 1. In a pin-tumbler cylinder lock, the combination with the cylinder and key-plug thereof, of a cylinder-extension for being fastened to the rear end of the said cylinder, a supplemental plug rotatably mounted in the said cylinder-extension, a standard bit carried by the said supplemental plug, and a coupler interposed between the supplemental plug and the key-plug.

2. In a duplex pin-tumbler cylinder lock, the combination with the cylinder, key-plug and eccentric plug thereof, of a cylinder-extension for being fastened to the rear end of the said cylinder, a supplemental plug rotatably mounted in the said cylinder-extension, a bit carried by the said supplemental plug, and a sliding coupler interposed between the said key-plug and the supplemental plug and sliding to compensate for the changes of alinement due to the rotation of the eccentric plug.

3. In a duplex pin-tumbler cylinder-lock, the combination with the cylinder thereof, of an eccentric plug mounted in the said cylinder for rotation therein, a key-plug eccentrically mounted in the said eccentric plug for rotation therein, a cylinder-extension for being fastened to the rear end of the said cylinder, a supplemental plug rotatably mounted in the said cylinder-extension, a standard bit secured to the said supplemental plug, and a sliding coupler interposed between the said key-plug and the said supplemental key-plug and sliding to compensate for their changes of alinement due to the rotation of the eccentric plug.

4. In a duplex pin-tumbler cylinder lock, the combination with the cylinder, eccentric plug and key-plug thereof, the key-plug being provided at its inner end with a transversely arranged groove, of a series of cylinder-extensions differentiated in length but alike at their ends, a supplemental -plug mounted in each of the said extensions, formed with a coupling groove and conformed in length to the length of the extension in which it is mounted, a standard bit attached to each of the said supplemental plugs, and a sliding coupler entering the specification in the presence of two subscribsaid grooves of the key-plug and suppleing Witnesses.

mental plug and sliding to equalize the JOHN H. SHAW. separation or non-alinement of the centers FRANK I. KIMBALL. of the key-plug and eccentric plug due to Witnesses: rotating the latter. SYDNEY F. SARGENT,

In testimony whereof, We have signed this BERTHA RAY.

Copies of this patent may be cbtained for five cents each, by addressing the commissioner of ZPatcnts, Washington, D. G. 

